Starting mechanism for internal combustion motors



March 20, 1934. J R THQNGER AL 1,951,637

STARTING MECHANISM FOR INTERNAL COMBUSTION MOTORS Filed May 9. 1931 2Sheets-Sheet 1 ATTORNEYS March 20, 1934. J, THQNGER r AL 1,951,637

STARTING MECHANISM FOR INTERNAL COMBUSTION MOTORS Filed May 9. 1931 2Sheets-Shet '2 (Mm/m ATTORNEYS Patented Mar. 20, 1934 STARTING MECHANISMFOR INTERNAL (IOMB'USTJION MQTORS John R. Thonger and. Oscar Denlrer,Milwaukee, Wis, assignors to lfarley flavidson Motor Company, Milwaukee,Wis, a corporation of Wisconsin Application May 9, 1931, Serial No.536,215

11 Claims. (Ci. 127 185) Our invention relates to improvements instarting mechanism for internal combusti n motors.

Our objects are to provide an improved starting mechanism promotingconvenience and safety in motor starting operations.

More specifically stated, our objects are-to provide efficient and safemeans for rotating the crank shaft of the motor with the aid ofreduction gear mechanism, the driven member of which is normallydisengaged from the engine shaft but automatically becomes engagedtherewith during operationof the starting lever; to provide startingmechanism having reduction gears in constant mesh and associated clutchmechanism in which a driving connection will be automatically made withthe engine shaft only during a portion of the movement of the lever inone direction; to provide means whereby the starting lever will beautomatically returned to its normal position if manually released whenin any other position; to provide reliable, positively acting, throw-outmechanism for automatically disengaging the driven member f the startinggear from the motor shaft if the motor backfires, i. e., if the motor inthe wrong direction; and in general, to so organize a starting mechanismthat a motor may be easily and safely started by mere reciprocation of astarting lever after proper adjustment of its ignition switch andthrottle valve, no manual adjustments or other attention being requiredto effect the coupling of the starting mechanism to the motor shaft atthe proper time.

In the drawings:

Figure 1 is a front elevation of our invention, showing the same appliedto a motor casing.

Figure 2 is a side elevation of the same, with parts broken away andother parts illustrated in vertical section.

Figure 3 is a plan view of the driven member and associated parts, afragment of the sector gear being also illustrated, and the throw-outcam dog being shown in clutch disengaging position.

Figure 4 is a view showing the cam dog in normal position and the sectorgear in position allowing the associated pinion to engage the motorshaft.

Figure 5 is a side elevation showing a modification, wherein the throwout cam dog is associated with starting crank adapted to be directlycoupled to the motor shaft.

Figure 6 is an enlarged fragmentary view of the clutch, cain dog, andassociated parts, with portions shown in vertical section.

Figure '7 is a plan view of the parts shown in Figure 6, with a portionof the clutch housing partially broken away.

Like parts are identified by the same reference characters throughoutthe several views.

In the structure shown in Figures 1 to 4, invs, the crank shaft 10 ofthe motor is prowith a clutch member 11 engageable by clutch 3 .vs 3.2projecting from the side face of pinion i3, slidably mounted on asupporting stud shaft whereby the jaws 12 may be carried into and out ofengagement with the teeth f clutch member 11 by movement of the pinionon its stud shaft. The pinion may be rotated by a toothed sector 15carried by an oscillatory starting shaft 16 to which the sector fixedlysecured. T e shaft 16 has an arm l7 provided with a socketed end portion18 adapted to receive a rod is which serves as a lever to manuallyoscillate the shaft.

The extent of the sector 15 is such that it recontinuous mesh with thepinion while the lever is i sing oscillated, and the pinion is ofsufficient width to allow it to shift on its stud shaft into out ofclutch engagement with the motor shaft while remaining in mesh with theteeth of the sector. Therefore, during the movement of the sector andits actuating lever in one direction the pinion may be in clutchengagement with the motor rank shaft for at least a portion of suchstroke, and during the return stroke the pinion may be shifted on itsstud shaft to release the motor shaft.

In the construction. illustrated, means are provided for holding thepinion out of engagement with the motor shaft during the initial portionof the actuating stroke of the lever and for retracting the pinion fromengagement with the motor shaft during the final portion of theretractive stroke, this being incident to the operation of the pinionactuating mechanism hereinafter described.

The shaft 16 is mounted in suitable bearings 20 carried by the framebracket 21. This bracket has an upwardly projecting arm 22 to which thestud shaft 14 is secured. A tension spring 25 is coiled about thestarting shaft 16, with one end anchored to the shaft or its arm 1'7 andthe other end attached to the frame bracket at 26 (Figure 2). Thisspring tends to swing the starting lever to normal position, whereby ifthe lever is manually released when out of such po sition it will beimmediately returned to the normal position by the spring 25.

To automatically shift the pinion 13 into engagement with the motorshaft, a compression spring so is interposed between the pinion 13 and ahub 31 of the frame bracket arm 22, the pinion provided with a suitablehub to receive the other end of said spring whereby the pi. on 13 willbe urged by the spring in the direction of the motor shaft clutch member11. The pinion teeth and those of the clutch member 11 are of ratchettype, with oblique faces at one side permitting independent rotation ofthe motor shaft in clockwise direction by pushing the pinion outwardlyto allow the points of the teeth to clear.

Normally, however, the pinion is held in the retracted position by ashoe 33, secured to the inner side of the sector gear 15 and providedwith an upwardly projecting flange-like portion in a position to bearagainst the inner side face of the pinion 13 when in registry therewith.The shoe has an extension 3% of its pinion engaging flange, whichdiverges from the sector in the direction of the end opposite that whichnormally engages the pinion, whereby, after the starting lever has beenswung to the left, (counter-clockwise), in a motor starting stroke, theshoe 33 will first be moved to the left as viewed in Fig. 4 far enoughto release the pinion and allow the spring to automatically move itinwardly to engage its clutch teeth with those on the motor shaft clutchmember. The oblique portion 3a of the shoe is so disposed that upon thereturn stroke it will engage the inner side of the pinion and force itoutwardly as the sector approaches normal position, thereby disengagingthe pinion from the motor shaft.

Back fire throw-out mechanism is also provided. The crank case 36 has asupporting projection 3? to which an oscillatory spring-actuated cam dog38 is pivoted. This dog is provided with an arm 41 which bears obliquelyagainst the ends of the pinion teeth and slides across the ends of theteeth when the pinion is being rotated in a motor starting direction.The arm is urged by the spring between the teeth, but owing to itsoblique position, it is pushed out from between them during suchrotation. But whenever the pinion is rotated in the opposite direction,the teeth engage this arm 41 and rotate the dog until its cam surface 42engages the pinion and pushes the pinion outwardly to disengage it fromthe motor shaft.

In the construction illustrated in Figures 5, 6, and '7, the startingcrank 19a is formed for direct clutch engagement with the motor shaft.Its shaft portion 16a is supported by an arm 21a, provided with abearing member 20a, and the inner end of this shaft portion 16a isprovided with a cylindrical head 45 in which a plunger 48 is socketed,this plunger having a projecting ratchet tooth 12a adapted to engagebetween the teeth of the motor shaft clutch member 11a. The plunger i8is provided with a laterally projecting pin 50 extending through a slot51 in the wall of the plunger socket, this pin preventing the plungerfrom rotating in its socket.

A compression spring 52 is seated between the plunger and the base ofthe socket and tends to urge the tooth 12a in the direction of the motorclutch member 11a while allowing the tooth to yield and pass over theends of the clutch teeth during retractive movements of the crank. Theportion of the head 45 through which the slot 51 extends has a fiatsurface 53 to which a cam dog 38a is pivoted at 55. This dog has aratchet tooth 56 in position for engagement with ratchet teeth =7 formedat the outer end of a sleeve-like projection 3%; which encircles theclutch member 110: and is attached to the wall of the motor crank case,as indicated at 58. The cam dog 38a also has an arm 66 which normallybears against the pin 50 which guides the plunger 48.

It will be observed that the ratchet teeth 5'? are pitched in theopposite direction from those of the clutch member 11a and the arm ortooth 56 of the cam dog is reversely pitched, whereby if the motorback-fires, thereby tending to rotate the motor shaft and associatedclutch member 11a in a counter-clockwise direction, the arm 56 of thecam dog will engage one of the teeth 5'? and the cam will be oscillatedin a clockwise direction, thereby causing its arm 50 to push against thepin 50 and retract the clutch dog 12a by pushing the plunger it into itssocket against the resistance of the spring 52. As soon as the clutchdog 12a is released om the teeth of the clutch member lie the crankwill, of course, be released. from connection with the motor shaft.

It will be observed that in the construction shown in Figures 1 to a,inclusive, the back-fire throw-out cam is supporter f om the crank caseof the motor, whereas in Figures 5, 6, and '7 it is supported from thestarting crank hat and the associated ratchet is supported from thecrank casing. The principle of operation is substantially the same, andin a broad aspect, one to be regarded as the mechanical converse ofother. In either case, the cam dog operates to force a retraction of thestarting crank, clutch teeth, or clutch tooth, from the motor shaftratchet clutch whenever the motor shaft revolves in a counter-clockwisedirection, such as occurs when the motor back fires.

We are aware that attempts have heretofore been made to providethrow-out cam dogs in a somewhat similar organization to thatillustrated in Figures 5, 6, and '7, but we believe we are the first toprovide a cam dog which can be relied upon to positively retract orseparate the clutch members without injury to the operator. In bothforms of construclion as illustrated herein the engagement of the camdog arm bet? een the teeth from which the cam action is derived positiveand certain in operation, although the arm freely slides across the endsof the teeth when the motor shaft is being revolved in the properdirection. Also, in both forms of construction, the oscillation of thecam by the positively engaged arm is certain to effect an instant andcomplete release of the starting crank An important feature of ourimproved throwout mechanism includes the provision of means forautomatically and yieldingly urging the starter clutch member in thedirection of the motor shaft clutch member.

We claim:

1. The combination with a motor crank shaft and associated motor clutchmember, of a starter shaft aligned with the motor shaft, a manuallyrotatable one-way acting starter member movable along the starter shaftinto and out of engagement with the motor clutch member, means foryieldingly urging the starter member in the direction of the motorclutch member, a cam responsive to reverse rotation of the motor shaftfor retracting the starter member from the motor clutch member, said camhaving an actuating finger adapted to normally bear obliquely againstthe side of the starter member in a position to be positively engagedthereby during reverse rotation of the starter member.

2. The combination with a motor crank shaft and associated motor clutchmember, of a starter shaft aligned wit the motor shaft, a manuallyrotatable one-way acting starter member movable along the starter shaftinto and out of engagement with the motor clutch member, means for yieldingly urging the starter member in the direction of the motor clutchmember, a cam responsive to reverse rotation of the motor shaft forretracting the starter member from the motor clutch memher, and amanually operable toothed sector provided with a laterally ofi'set shoehaving a radially extending flange adapted to move with a wedging actionupon starter member to retract the latter dur g final movement of thesector to normal posit on, starter member having poripheral teethcontinuous mesh with the manually operable toothed sector.

3. The combination with a motor shaft provided with a one-way actingclutch member, of a pinion having its axis aligned with that of themotor shaft and provided with a counter-part clutch member, said pinionbeing axially movable along said axis to bring the clutch me; and out ofengagement, a compression on ng arranged to urge said pinion into clutchengaging position, a manually operable gear member in continuous meshwith said pinion and provided with a laterally offset shoe having aflange provided with an oblique portion movable along the side of thepinion occupied by the clutch to progressively retract the pinion duringfinal move ment of the gear member to normal position hold the pinionwith the clutch members out of engagement when the gear is in normal 1:-tion, said shoe being formed to release the pinion spring actuationafter an initial rnotor starting operation of said gear member.

l. The combination with a motor shaft provided with a one-way actingclutch member, of a pinion having its axis aligned with that of themotor shaft and provided with a counteriart clutch member, said pinionbeing axially rho-v able along to bring the clutch members into and outof engagement, a compression spring arranged to urge said pinion intoclutch enga ing position, a manually operable gear member in continuousmesh with said pinion and provided with a shoe adapted to engage andretract the pinion when the gear is in normal position, said shoe havinga radially extending z-novable along the side of the pinion occupied bythe clutch member during an initial movement or the gear member fromnormal position and having an oblique portion adapted to progressivelyretract the pinion during the final portion of the return stroke of thegear member, and a throw-out cam responsive to reverse rotation of themotor shaft for retracting the pinion against the tension of itsctuating spring.

5. In a motor starting mechanism, the coinbination with a starting p onwith a one-way acting clutch on its inner side face, a sector hav gteeth in continuous with said pinion provided or shoe having a radiallyextending flan e oblique to the face of the pinion at one er a d adaptedto engage and shift the pinion axially to clutch re tracting positionwhen the go r is approaching normal position, and for automaticallyshifting the pinion the other direction wren released by together withan cam provided with ch!" 1 releasing face and having an arm in positionfor oblique engagement between the of the pinion by the arm may slide ofthe teeth when the pinion rotating in one direction and be engagedbetween the teeth during relative tation in the other direction to swingcam to clutch releasing position.

6. In a motor starting mechanism, the combi" nation with a startingpinion provided with a oneway acting clutch on its inner side face, asector gear having teeth in continuous mesh with said pinion andprovided with an offset shoe having a radially extending flange obliqueto the side face of the pinion at one end and adapted to engage andshift the pinion axially to clutch retracting position when the gear isapproaching normal position, and means for automatically shifting thepinion in the other direction when released by said shoe, together witha cam provided with a pinion retracting face and having a tooth inposition for oblique engagement between the ends of the pi, on teeth, toswing the cam to clutc releasing position when the teeth act upon saidin one dire :ion, said can: being provided with a spring adapted to urgethe cam arm in the direction. of the pinion teeth.

l. in a motor starter, the combination with an axially movable clutchpinion, of a pivoted knock out cam having a cam actuating fingerengageable between projections on said pinion relatively movable andnormally oblique with respect tosaid cam, said cam having a curved bodyportion adapted to be brought by said finger into pinion shiftingposition when the normal direction of pinion rotation is reversed.

8. In a motor starter, the combination with a shiftable clutch pinion,of a knock out cam pivoted to a relatively stationary support at oneside or" the pinion and having a cam actuating finger adapted to slideover the ends of the pin ion teeth when the pinion is actuated in onedirection, a cam actuating spring for urging the finger in the directionof the pinion teeth, said cam having a curved body portion adapted to bebrought by the into engagement with the side of the pinion to shift thelatter into a clutch releasing position when the rotation of the pinionis reversed.

9. A motor starter having an axially shiftable pinion oer engageablewith a motor shaft, in combination with a sector gear for rotating thepinion, a laterally offset pinion shifting member at one end of thesector engageable with the pinion when sector is at and its normalposition and a knock out provided with a one-way acting cain actuatingmember adapted to swing the cam into position for shifting the pinion toa clutch retracting position when the rotary motion of the pinion isreversed.

1c. in a motor starter having a clutch member provided with a clutchrotating pinion shiftable to engage and retract the clutch member, aknock out cam for shifting the pinion to clutch retractposition when therotation of the pinion is reversed from normal direction and a one-wayacting cam actuating member integral with said knock out cam responsiveto reverse rotation of the pinion.

1i. a motor starter having a clutch memprovided with a clutch rotatingpinion shiftable to engage and retract the clutch member, a lznocl: outcam for shifting the pinion to clutch retracting position when therotation of the pinion is reversed from normal direction and a one-wayacting caro actuating member integral with said knock out can? andresponsive to reverse rotation of the pinion, said cam actuating membercomprising a finger positioned for norinal sliding engagement betweenthe ends of the pinion teeth.

JOHN R. THONGER. OSCAR DENKER.

provided with an associated clutch inern-

